沃尔巴克氏菌调控小茶尺蠖和灰茶尺蠖杂交卵孵化

【目的】明确沃尔巴克氏菌Wolbachia对茶尺蠖两近缘种杂交卵孵化的影响及相关机制。【方法】使用2.5 mg/mL四环素浸液处理1 min后的新鲜茶树叶片连续饲喂灰茶尺蠖Ectropis grisescens幼虫3代，建立不携带Wolbachia的灰茶尺蠖种群。通过携带和不携带Wolbachia的灰茶尺蠖成虫分别与小茶尺蠖E. obliqua成虫进行杂交，探究Wolbachia对二者杂交卵孵化的影响。同时利用iTRAQ技术检测并分析携带和不携带Wolbachia的灰茶尺蠖精子蛋白的差异。【结果】与自然携带Wolbachia的灰茶尺蠖相比，去除Wolbachia后的灰茶尺蠖与小茶尺蠖杂交卵孵化率从3.92%显著提高到56.20%，表明Wolbachia诱导胞 质不亲合。精子蛋白差异分析显示，携带和不携带Wolbachia的灰茶尺蠖的精子蛋白中，共有128个蛋白显著差异表达，其中KEGG数据库注释到45个差异蛋白富集到鞘脂类代谢、唾液分泌、溶酶体、鞘脂信号通路和鞘糖脂生物合成等106个通路中，其中鞘脂类代谢通路中与神经酰胺合成相关的神经酰胺酶和磷酸酯酶显著上调表达。【结论】共生菌Wolbachia通过胞质不亲和作用介导了茶尺蠖两近缘种间的合子前生殖隔离，导致杂交卵的孵化率显著下降；Wolbachia可能通过鞘脂代谢通路实现了对雄性精子蛋白的修饰。

Wolbachia regulates the egg hatching of hybrids of Ectropis obliqua andE. grisescens(Lepidoptera: Geometridae)

【Aim】 The objective of this study is to reveal the impacts of Wolbachia on theegg hatching of hybrids of two sibling tea geometrids and the underlying mechanism.【Methods】 A subset of Ectropis grisescens larvae were fed with fresh tea leaves soaked in2.5 mg/mL tetracycline solution for 1 min to remove Wolbachia. E. grisescens populationswithout Wolbachia were established after being fed with tetracycline-treated tea leavesfor three generations. E. obliqua adults were hybridized with E. grisescens adults with andwithout Wolbachia to produce hybrids for the investigation of the impacts of Wolbachia onthe egg hatching. The iTRAQ technique was used to detect and analyze the differences insperm proteins between E. grisescens with and without Wolbachia. 【Results】 When Wolbachiawas removed from E. grisescens, the egg hatching rates of hybrids between E. grisescens andE. obliqua were significantly increased from 3.92% to 56.20%, indicating that Wolbachiainduced cytoplasmic incompatibility. Results of differential sperm proteins analysis showedthat a total of 128 proteins were confirmed to have significantly different expressionlevels in sperms of E. grisescens with and without Wolbachia. According to the KEGGdatabase, 45 differential proteins were enriched in 106 pathways, including sphingolipidmetabolism, salivary secretion, lysosome, sphingolipid signaling, sphingolipidbiosynthesis, etc. Among them the expression levels of ceramidases and phosphatases relatedto ceramide synthesis in the sphingolipid metabolic pathway were significantlyup-regulated. 【Conclusion】 The symbiotic bacterium, Wolbachia, mediates the prezygoticreproductive isolation between the two sibling tea geometrids through cytoplasmicincompatibility, leading to a significant decrease in the egg hatching rate of hybrids. Theobserved cytoplasmic incompatibility may be attributable to the modification of the malesperm proteins caused by the impacts of Wolbachia on the sphingolipid metabolism pathway.